Bi-directional time delay valve



June 21, 1966 W. D. LUDWIG 3,256,906

BI-DIRECTIONAL TIME DELAY VALVE Filed Feb. 5, 1963 5 Sheets-Sheet lINVENTOR. WALTER D. LUDWIG 1 41 WyM ATTOR N EYS June 21, 1966 w. D.LUDWIG [BL-DIRECTIONAL TIME DELAY VALVE 5 Sheets-Sheet 2 Filed Feb.

m 0W D mu V L m D R m L A W ATTORNEYS June 21, 1966 w. D. LUDWIGBI-DIRECTIONAL TIME DELAY VALVE 5 Sheets-Sheet 5 Filed Feb.

ATTORNEYS United States Patent 0 3,256,906 BI-DIRECTIONAL TIME DELAYVALVE Walter D. Ludwig, 3865 Lincoln Drive, Bloomfield Township, OaklandCounty, Mich.

Filed Feb. 5, 1963, Ser. No. 256,322 15 Claims. (Cl. 137-493) Thisinvention relates generally to time delay apparatuses for controllingthe flow of pressurized fluid in a fluid circuit, and more particularlyto a time delay air apparatus which is adapted to function independentof any valve and which can be used at any point in a pressurized fluidcircuit exclusive of an operating valve.

The prior art time delay air units incorporate the time delay structureas an integral part of an operating valve and the prior art delay airunits can only be employed with the specific incorporated operatingvalve structure. This is a disadvantage because in order to get a timedelay function in a pressurized fluid circuit, it is necessary topurchase a certain and often undesired attached operating valve. Afurther disadvantage of the prior art time delay units is that theyrequire disassembly' and adjustment when they are changed from atiming-in to a timing-out operating position, and the same requirementsmust be met when reversing the aforementioned connection. Anotherdisadvantage of the, prior art time delay air units is that the timedelay period is governed or controlled by the particular type of valvewith which it is combined, whereby the versatility of the time delayunit is restricted- Still another disadvantage of the existing timedelay air units is that they are constructed with dead end passagewayswhich normally collect contaminates carried by the pressurized fluid. Afurther disadvantage of prior art time delay units is that the timingsequence tends to vary greatly as the system pressure fluctuates.

Accordingly, it is an important object of the present invention toprovide a time delay unit which is adapted to be used in any pressurizedfluid circuit, exclusive of an operating valve, and which can beadjusted to various desired time delay periods.

It is another object of the present invention to provide a novel andimproved time delay unit for use in pressurized fluid circuits and whichmay be connected in such circuits between a directional flow controlvalve and a fluid cylinder or valve to provide timing-in operations, ortiming-out operations wherein the timing-out cycle is not started untilthe pressure is released at the primary source, and which can be furtheremployed in a pressurized fluid circuit for timing fluid flow in onlyone direction, and providing free flow of the fluid in the otherdirection.

It is still another object of the present invention to provide a noveland improved time delay unit for use in pressurized fluid circuits whichis constructed so as to purge water and dirt which may be carried alongwith the fluid.

' It is a further object of the present invention to provide a novel andimproved time delay unit which may be used in any pressurized fluidcircuit but which is especial ly adapted for use in pressurized aircircuits, and which includes a body having a pair of ports for fluidentrance and exit operations, a passageway connecting said ports,

a flow valve in said passageway for controlling fluid flow therethrough,accumulator means for opening said flow valve, means fornormallymaintaining said flow valve in a closed position when saidaccumulator means is inoperative, pressurized fluid metering means foradmitting a metered flow of said fluid into said accumulator means foroperating the same in predetermined timed cycles for timing the openingand closing of said flow valve to provide a delayed flow of pressurizedfluid between the ports when the fluid moves through the passageway inone direction, and a free flow of pressurized fluid when the fluid movesthrough the passageway in the opposite direction.

It is still a further object of the present invention to provide a noveland improved time delay unit that is not as susceptible to variations intiming sequence, due to fluctuations in system pressures, by maintaininga constant relationship between the system pressure and the pressurerequired to open the flow valve, and by utilizing the same systempressure which acts to oppose the opening of the flow valve as thesource of metered pressure for the accumulator means for opening theflow valve so that a variation in the system pressure produces acompensating variation in the rate of metered flow to the accumulatormeans.

Other objects, features and advantages of this invention will beapparent from the following detailed description and appended claims,reference being had to the accompanying drawings forming a part of thespecification.

In the drawings: a

FIG. I is a full size, side elevational view of a time delay apparatusmade in accordance with the principles of the present invention;

FIG. 2 is aleft end, elevational view of the structure illustrated inFIG. 1;

FIG. 3 is a top plan view of the structure illustrated in FIG. 1; I

FIG. 4 is a bottom plan view of the structure illustrated in FIG. 1;

FIG. 5 is an enlarged, central elevational sectional view of thestructure illustrated in FIG. 2, taken along the line 5-5 thereof andlooking'in the direction of the arrows;

FIG. 6 is a fragmentary, elevational sectional view,

illustrated in FIG. 6, taken along the line 77 thereof and looking inthe direction of the arrows;

FIG. 8 is a fragmentary, horizontal sectional view of the structureillustrated in FIG. 6, taken along the line 8-8 thereof and looking inthe direction of the arrows;

FIG. 9 is a horizontal sectional view of the structure illustrated inFIG. 1, taken along the line 9-9 thereof and looking in the direction ofthe arrows; and, FIG. 10 is a horizontal sectional view of the structureillustrated in FIG. 1, taken along the line 1010 thereof and looking inthe direction of the arrows.

The time delay apparatus of the present invention is especially adaptedto be used in pressurized air circuits. The time delay apparatus of thepresent invention is adapted to be operatively connected between adevice to be controlled, as for example, an air cylinder, and aconventional directional flow control valve for the purpose of timing-inand timing-out operations. The time delay apparatus of the presentinvention may also be used for other purposes as, for'example, in an airline leading to a directional flow control valve to time the operationof that valve for timing the air-in and air-out periods of air flowingto the directional flow control valve.

Referring now to the drawings, the numeral 10 generally indicates thetime delay unit body which is preferably made from aluminum or any othersuitable material. As shown in FIGS. 5, 6 and 7, the body 10 is providedon the right end thereof with a control fluid chamber 11 and on the leftend thereof with a free flow fluid chamber 12. The chamber 11 isprovided with the entrance port 13 which is circular and threaded forthe reception of the pipe bushing 15. The chamber 12 is provided withthe exit port 14 which is also circular and threaded for the receptionof the pipe bushing 16. The

chamber 11 extends inwardly over the chamber 12. The.

Patented June 21, 1966 inner ends of the chambers 11 and 12 aresubstantially rectangular in vertical cross-section. As shown in FIG. 5,the inner overlapping ends of the chambers 11, and 12 are interconnectedby the valve bore 17. As shown in FIG. 5, the ports 13 and 14 arealigned. The valve bore 17 is vertically disposed at an angleperpendicular to the longitudinally extended chambers 11 and 12. Thechambers 11 and 12 and the valve bore 17 form a pressurized fluidpassageway through the body 10.

The time delay unit includes a metering means comprising the meteringtube generally indicated by the numeral 18. The tube 18 is verticallydisposed and extends through the valve bore 17. Slidably mounted on themetering tube 18 is a check valve or flow valve generally indicated bythe numeral 19 for blocking fluid flow through the valve bore 17. Thecheck valve 19 is provided with a cylindrical body on the upper end ofwhich is formed a sealing ring seat 20 by means of the vertically spacedapart, outwardly extended shoulders 21 and 22. A moulded sealing ring 23is operatively mounted in the seat 20 and engages the valve bore 17 whenthe valve 19 is in the closed position as shown in FIG. 5. The sealingring 23 may be made from any suitable sealing ring material as, forexample, a suitable rubber or the like. As shown in FIG. 5, a conicalcompression spring 24 is mounted around the upper end of the meteringtube 18 and is adapted to move the valve 19 to the closed position. Theupper end of the spring 24 engages the upper wall of the chamber 11 andthe lower end of the spring 24 engages the shoulder 22 of the valve 19.

As shown in FIGS. 5, 9 and 10, the lower end of the metering tube 18extends into an accumulator chamber which is formed in the lower end ofthe time delay unit. The accumulator chamber includes the centralcircular portion 25 and the end portions 26 and 27 which are formed inthe lower end of the body 10. The accumulator chamber further includes aplurality of communicating chamber portions in the accumulator cover,generally indicated by the numeral 28, and which is substantiallyrectangularly shaped. The accumulator cover 28 may be made from anysuitable material as, for example, die cast zinc. Formed in theaccumulator cover are the accumulator chamber portions 29 and 30 whichare interconnected by means of the central chamber portion 31. The coverchamber portions 29 and 30 are disposed under the chamber portions 26and 27, respectively, formed in the body 10. The accumulator chamberportion 25 functions as an accumulator piston [cylinder as more fullydescribed hereinafter. The cover chamber portion 31 is disposed underthe body chamber portion 25 and communicates with the same. Theaccumulator cover 28 is provided with the inwardly extended projections32 and 33 which are best seen in FIGS. 7 and 9. The projections 32 and33 have an upper flat surface which is even or level with the uppersurface of the cover. The projections 32 and 33 extend inwardly underthe accumulator chamber portion 25. The accmulator cover 28 isdetachably connected to the body 10 by any suitable means as, forexample, by a plurality of machine screws 35. The cover 28 is providedwith a pair of integral upwardly extended locating dowels 36 and 37which are adapted to be seated in the holes 38 and 39, respectively,formed on the lower side of the body 10. A suitable gasket 34 isinterposed between the cover 28 and the body 10.

As shown in FIGS. and 7, the upper end of the accumulator chamberportion 25 is vented to the atmosphere by means of the passageway 40.The accumulator chamber is vented to the atmosphere by a secondpassageway which includes the vertical bore 41 in the body which has thelower end thereof communicating with the cover chamber portion 29.Pressed into the lower end of the bore 41 is a tube 42 which extends towithin approximately & of 'an inch of the lower end of the accumulatorchamber portion 29. As shown in FIG. 5, the upper end of the vent bore41 communicates with the reduced vertical bore 43 which in turncommunicates with the horizontal bore 44. The bore communicates with theenlarged exhaust piston chamber 45 which is open at the outer endthereof to the control fluid chamber 11. The inner end of the pistonchamber 45 is vented to the atmospheric by means of the drilledpassageway 46.- Slidably mounted in the piston chamber 45 is the exhaustpiston 47 which is provided with a' suitable O-ring sealing means 48.Mounted on the inner end of the piston 47 is a poppet sealing member 49for normally enclosing the outer end of the passage 44 when fluidpressure is admitted to the chamber 11. The cross sectional area of thepassage 44 is about of the cross sectional area of the piston 47 topermit the piston 47 to be held in the closed position against the endof the passage 44 when the fluid pressure in the chamber '11 fluctuatesor drops as compared to the pressure in the accumulator chamber. Forexample, if the pressure in the inletline dropped to about 20 pounds persquare inch and the pressure in the accumulator chamber was pounds persquare inch, the exhaust piston 47 would maintain the closed position tohold the flow valve 19 in the open position, as more fully describedhereinafter. The poppet seal 49 and piston 47 function to provide thepoppet valve or exhaust valve for controlling the exhaust of the fluidunder pressure from the accumulator chamber.

As shown in FIG. 5, a differential accumulator piston.

generally indicated by the numeral 50 is slidably mounted in thevertically disposed accumulator chamber portion or piston cylinder 25.The piston 50 is provided with the O-ring 51 on the lower end thereof.The upper end of the piston 50 is reduced as indicated by the numeral 52and is slidably mounted through the bore 53 formed in the chamber wallon the lower side of the free flow fluid chamber 12. A suitable O-ringsealing means 54 is mounted around the bore 53 for engagement with thepiston upper end 52. The piston 5t engages the lower end of the flowvalve 19 for moving this valve upwardly to the open position as shown inFIG. 6.

As shown in FIGS. 5, 6 and 7, the differential accumulator piston 50 isprovided with an axially formed bore 55 in which is slidably mounted thelower end of the metering tube 18. A suitable O-ring sealing means 56 ismounted in the upper end of the piston 50 for engagement with themetering tube 18. The metering tube 18 is provided with a suitableO-ring sealing means 57 for engagement with the tubular body of the flowvalve 19. The lower end of the metering tube 18 is provided with thecross slot 58 in which is slidably received the upwardly extended tongue59 which is integrally formed on the cover 28. The metering tube 18 isprovided with the axially extended bore 69a which forms the exit part ofthe metering passageway and which communicates at the lower end thereofwith the cross slot 58 and at the upper end thereof with the enlargedmetering valve chamber 60.

The body 10 is providedv with the upwardly extended projection 61 on theupper end thereof and formed in the projection 61 is an inwardlyextended cylindrical recess 62. As shown in FIGS. 5, 6 and 7, the upperend of the metering tube 18 extends through the control fluid chamber 11and through the bore 63 formed in the upper wall of the chamber 11 andinto the recess 62. A suitable O- ring sealing means 64 is mounted inthe wall of the bore 63 for engagement with the metering tube 18. Fluidunder pressure is adapted to be admitted to the metering valve chamber60 in the metering tube 18 from the chamber 11 by the followingdescribed structure.

The inner end of the recess 62 is-connected to the chamber 11 by meansof the inlet part of the metering passageway formed by the passage 65,the inlet valve chamber 66, the passage 67 and the enlarged circularbore 68. The upper end of the passage 65 communicates with the inner endof the recess 62. The lower end of the passage 65 communicates with theinlet valve chamber 66 in which is slidably mounted the inlet poppetvalve piston 70. Mounted on the inner end of the piston 70 is the poppetseal 72 which is adapted to block off the passage 67 during free flow offluid through the time delay apparatus. The inlet valve piston 70 isprovided with a suitable O-ring sealing means 71. A conventionalsintered bronze filter 69 is mounted in the enlarged bore 68. Thepistons 47 and 70 are similarly constructed.

As shown in FIGS. 5, 7 and 8, a vertically disposed, substantiallyV-shaped slot 73 is formed on the upper end of the metering tube 18 forcommunicating the metering valve chamber 60 with the inner end of thecylindrical recess 62. The operative portion or effective opening of theslot 73 is controlled by the rotatable metering valve 74 which isslidably mounted in the upper end of the valve chamber 60. A suitablesealing means 75 is mounted around the lower end of the valve 74. Theupper end of the metering valve 74 is splined, as indicated by thenumeral 76, for fixed seating engagement in the recess 77 formed in therotatable metering valve control knob 78. The outer surface of thecontrol or adjustment knob 78 is knurled.

As shown in FIGS. 5, 6 and 7, the metering valve control knob 78 isprovided with a circular flange 79 on the lower end thereof which isrotatably seated in the recess 62. A suitable O-ring sealing means 80 iscarried in the outer periphery of the flange 79 for engagement with thewall of the recess 62. A conventional snap ring 81 is mounted in agroove in the wall of the recess 62 and engages the upper side of thecontrol knob flange 79 for maintaining the knob in the recess 62. Aconventional wave washer 82 is mounted in the inner end of the recess 62below the control knob flange 79 and normally urges the control knobflange 79 upwardly against the snap ring 81. circular recess 83 formedon the lower side of the knob flange 79. The wave washer 82 maintainsthe control knob 78 in spaced apart relationship from the inner end ofthe recess 62 to permit pressurized fluid to flow under the control knob78 and through the slot 73 into the meter ing valve chamber 68. Tofacilitate the flow of pressurized fluid into the slot 73, the controlknob 78 is provided with the axial recess 84, on the inner end. thereof,which communicates with the wave washer recess 83. The upper end of themetering tube 18 is externally threaded and is threadably mounted in theinwardly extended thread axial bore 85.

The period of time delay provided by the apparatus of the presentinvention under any given inlet line pressure is set by adjusting themetering tube 18 upwardly or downwardly relative to the metering valve74 to increase or decrease the delay period, as desired. FIG. 5 showsthe metering tube 18 disposed at one end of its travel so as to providea maximum opening of the metering slot 73. FIG. 6 shows the meteringtube 18 adjusted upwardly whereby the rotatable metering valve 74 hasbeen moved downwardly into the valve chamber 60 to further enclose theslot 73 and increase the delay period. The smaller effective entrancearea of the slot 73 reduces the rate of flow of pressurized fluid intothe valve chamber 60. It will be seen that the metering tube 18 isadjusted upwardly and downwardly relative to the metering valve 74 by anappropriate rotation of the knob 78. When the knob 78 is rotatedclockwise, as viewed looking down on the valve as shown in FIG. 3, thetube 18 will be moved upwardly from the position shown in FIG. 5 to araised position as illustrated ir 1 FIG. 6. The knob 78 may be providedwith suitable calibration indicia to permit the user to adjust themetering valve 74 accurately relative to the slot 73 to predeterminedsettings so as to obtain the de- It will be understood that the height Isired time delay. and the width of the slot 73, and the size of themetering valve 74 and the valve chamber 60, may be made to anydimensions to obtain the desired rates of flow and timed delay. Forexample in one illustrative embodiment, the

The wave washer 82 is adapted to be seated in the 6 slot 73 wasapproximately .280 of an inch in height and .005 of an inch in width.

The time delay unit of the present invention is adapted for two primaryuses, namely, for timing-in and timing-out operations. A timing-inoperation in a fluid circuit for controlling the flow of pressurizedfluid to a fluid cylinder or the like comprises a time delay intervalduring the fluid inlet period, and a free flow of the fluid from thecylinder upon reversal of flow of fluid initiated by a signal from adirectional flow control valve in the circuit. A timing-out operation ina fluid circuit for controlling the flow of pressurized fluid from afluid cylinder or the like comprises a free flow of fluid during thefluid inlet period, and a time delay interval during the return flow offluid from the cylinder, which return flow is initiated by a signal froma directional flow control valve in the circuit.

For a timing-in operation the time delay unit is connected in apressurized air system so that the pressurized air enters from the rightside of the unit as viewed in FIG. 5, to provide a time delay controlover the pressurized air being supplied to air cylinder or the like. Thetiming-in operation starts when the directional flow control valve inthe system is operated to permit flow of pressurizedair to the timedelay apparatus. At the start of a timing-in operation the time delayapparatus would be in the condition shown in FIG. 5. The air underpressure would flow into the chamber 11 and against the accumulatorexhaust valve piston 47 to seal the accumulator chamber exhaust passage44. Air under pressure also passes through the filter 69 and thencethrough the passage 67 and against the metering means inlet valve piston70 to shift it to the left, as viewed in FIG. 5, to the open position.The pressurized air then flows through the piston chamber66 and thepassage 65 into the inner end of the metering control recess 62, andthence through the wave washer recess 83, the axial recess 84, andthrough the metering slot 73 into the metering valve chamber 60. Therate of flow of the pressurized air into the metering valve chamber 60would be determined by the effective open area of the slot 73 asdetermined by the position of the metering tube 18 with respect to themetering valve 74. The air under pressure passes from the metering valvechamber 60 downwardly through the metering tube axial bore 60a and intothe tongue slot 58. There is clearance between the tongue 59 and thediameter of the piston 55, as shown in FIG. 7, and the pressurized airwill pass into the accumulator chamber.

The air pressure will build up in the accumulator chamber until apredetermined air pressure is reached. The pressurized air in theaccumulator chamber acts on the lower end of the accumulatordifferential piston 50 and when the predetermined air pressure ispresent in the accumulator chamber, the accumulator piston 50 will bemoved upwardly and the flow valve 19 will be shifted to the openposition shown in FIG. 6 to permit free flow of pressurized air throughthe time delay unit to the device being controlled.

It will be seen from an inspection of FIGS. 7 and 9, that when theaccumulator piston 50 is in the inoperative position, it will be seatedon the cover projections 32 and 33, as indicated by the broken lines inFIG. 7, so as to decrease the initial effective operating area of thelower enlarged end of the piston. Substantially onehalf of thedifferential area of the piston 50 is thus covered, as compared to thearea of the flow valve being acted on by air in the control chamber,when the air pressure initially moves the accumulator piston 50upwardly. When the accumulator piston 50 breaks away from itsinoperative position, as shown in FIG. 5, the effective differentialoperating area of the piston increases in a substantial 2 to 1 ratio.This last mentioned feature of the time delay unit of the presentinvention provides a positive and complete opening of the flow valve 19,with a snap action, when the predetermined opening air pressure is builtup in the accumulator chamber.

When the inward flow of pressurized air to the device being controlledis reversed upon a signal from the directional flow control valve in theair system, the air will flow through the time delay unit with a freeflow action to the right, as viewed in FIG. 5. The exhausting air underpressure will move the inlet valve piston 70 to the closed position andthe air pressure in the accumulator chamber will move the exhaust valvepiston 47 to the open position to permit the air in the accumulatorchamber to be exhausted through the vent passage 46. The exhausting airunder pressure in the free flow chamber 12 will engage the reduced innerend of the accumulator piston 50 and move it downwardly to the positionshown in FIG. 5. The flow valve 19 will be held in the open positionshown in FIG. 6 by means of the exhausting air moving successivelythrough the chambers 12 and 11. When the air pressure in the free flowchamber 12 drops a predetermined amount, the spring 24 will close theflow valve 19 and the delay unit will be in a condition for a furthertiming-in operation.

For a timing-out operation the delay apparatus would be connected in apressurized air system to permit free flow of pressurized air throughthe delay apparatus from the left side thereof, as viewed in FIG. 5, andinto the device being controlled upon a signal from the directional flowcontrol valve in the system. The pressurized air would flow freely tothe cylinder or other device being controlled because the flow valve 19would be shifted to the open position shown in FIG. 6 by means of theair pressure operating on the lower side thereof. The

pressurized air would engage the inlet valve piston 70 and shift it tothe right to the closed position as shown in FIG. 5. The pressurized airpassing through chamber 11 would also shift the accumulator valve piston47 to the closed position, to the left as viewed in FIG, 5, to close theexhaust system for the accumulator chamber.

When the cylinder or other device being operated by the free flow ofpressurized air has completed its function, an exhaust signal would begiven by the directional flow control valve in the system andthemetering means would be operated to provide a timing-out delay period asdescribed hereinafter. The pressurized air in the chamber 12 would beexhausted and the pressurized air in the system between the device beingcontrolled and the .flow valve 19 would be trapped. The trappedpressurized air would shift the metering means inlet valve piston 70 tothe open position, to the left as viewed in FIG. 5, to admit pressurizedair to the metering valve chamber 60. The pressurized air will flow fromthe metering valve chamber v60 down into the accumulator chamber andbuild up to the point where the differential accumulator piston 50 willbe moved upwardly to the position shown in FIG. 6 to open the flow valve19 and terminate the timing-out delay period. The pressurized airpressure is thus exhausted from the device being controlled and thedirectional flow control valve of the system could be operated toinitiate a new timing-out operation.

The delay unit of the present invention is adapted to provide a widerange of time delay. For example, in a fluid system where the linepressure is about 80 pounds per square inch with a possible plus orminus fluctuation of 10 pounds per square inch, the time delay unit maybe adjusted to provide time delays of from zero to one minute durationwith an accuracy of within two percent.

While it will be apparent that the preferred embodiment of the inventionherein disclosed is well calculated to fulfill the objects above stated,it will be appreciated that the invention is susceptible tomodification, variation and change without departing from the properscope or fair meaning of the subjoined claims.

What I claim is:

1. A time delay apparatus for controlling the flow of pressurized fluidin a fluid circuit, comprising: a body having a first port and a secondport; a passageway formed through said body for connecting said ports; aflow valve flow valve for positioning the flow valve in the other ofsaid positions after a predetermined time delay; and,

pressurized fluid metering means in said body for admitting a meteredflow of pressurized fluid into said accumulator means for operating thesame in the predetermined time delay cycle for timing the operation ofsaid accumulator means.

2. A time delay apparatus for controlling the flow of pressurized fluidin a fluid circuit, comprising: a body having a first port and a secondport; a passageway formed through said body for connecting said ports; aflow valve operatively mounted in said passageway for controllingpressurized fluid flow therethrough and being shiftable between a closedposition and an open position; means engageable with said flow valve forpositioning the flow valve in one of said positions; accumulator meansin said body including an accumulator'chamber and an accumulator pistonoperatively mounted in said chamber movable relative to and engageablewith said flow valve for positioning the flow valve in the other of saidpositions after a predetermined time delay; and, pressurized fluidmetering means in said body for admitting a metered flow of pressurizedfluid into said accumulator chamber for moving said piston in thepredetermined time delay cycle for timing the operation of saidaccumulator means.

3. A time delay apparatus for controlling the flow of pressurized fluidin a fluid circuit, comprising: a body having a first port and a secondport; a passageway formed through said body for connecting said portsand including a control fluid chamber and a free flow fluid chamberconnected by a valve bore; a flow valve operatively mounted in saidvalve bore for controlling pressurized fluid flow therethrough and beingshiftable between a closed position and an open position; meansengageable with said flow valve for positioning the flow valve in one ofsaid positions; accumulator means in said body including an accumulatorchamber and an accumulator piston operatively mounted in said chambermovable relative to and engagable with said flow valve for positioningthe flow valve in the other of said positions after a predetermined timedelay; and, pressurized fluid metering means in said body for admittinga metered flow of pressurized fluid into said accumulator chamber formoving said piston in the predetermined time delay cycle for timing theoperation of the accumulator means.

4. A time delay apparatus as defined in claim 3, wherein: saidaccumulator means includes an exhaust means for exhausting thepressurizedfluid from the accumulator chamber to the exterior of thebody when a predetermined pressure differential exists between the fluidpressures in the accumulator chamber and the control fluid chamber.

5. A time delay apparatus as defined in claim 4, wherein: said exhaustmeans includes an exhaust passageway, an exhaust valve operativelymounted in said exhaust passageway and being in communication with saidcontrol fluid chamber and shiftable by fluid under pressure in thecontrol fluid chamber to a normally closed position to block saidexhaust passageway so long as a predetermined pressure differentialexists between the fluid pressure in said control fluid chamber and thefluid pressure in said accumulator chamber.

6. A time delay apparatus as defined in claim 5, wherein: the surfacearea of the exhaust valve engageable by the pressurized fluid in thecontrol fluid chamber is greater than the cross sectional area of theexhaust passageway closed by the exhaust valve to provide a pressuredifferential on the exhaust valve to maintain it in the closed positionwhen the fluid pressure in the control fluid chamber fluctuates.

7. A time delay apparatus as defined in claim 3, wherein: the meansengageable with said flow valve for positioning the flow valve in saidone of said positions is a spring means disposed in said control fluidchamber and which is compressible to permit the accumulator piston toposition the flow valve in said other position and adapted to positionthe flow valve in said one position without assistance from theaccumulator piston.

8. A time delay apparatus as defined in claim 3, wherein: saidpressurized fluid metering means includes a metering fluid passagewayinterconnecting said control fluid chamber and said accumulator chamber,an adjustable metering valve operatively mounted in said meteringpassageway to provide a predetermined timed flow of pressurized fluidinto said accumulator chamber, and a pressurized fluid inlet valve insaid metering passageway and shiftable to an open position by fluidentering the metering passageway, and being in communication with saidfree flow fluid chamber and shiftable by fluid under pressure in saidfree flow fluid chamber to a closed position to block said meteringpassageway when a predetermined pressure diflerential exists between thefluid pressure in said control fluid chamber and the fluid pressure insaid free flow fluid chamber.

9. A time delay apparatus as defined in claim 8, wherein: the Workingsurface area of the fluid inlet valve engageable by the pressurizedfluid in the free flow fluid chamber is greater than the cross sectionalarea of the metering passageway area blocked by the inlet valve.

-10. A time delay apparatus as defined in claim 8, wherein: saidmetering valve includes a tu-be having a bore therethrough forming anexit part of said metering passageway, one end of said bore beingconnected to said accumulator chamber, the other end of said bore beingconnected to a metering valve chamber, said metering valve chamberhaving a slot formed in one side thereof and communicating with an inletpart of the metering passageway, a valve pin mounted in said meteringvalve chamber, means for adjusting said tube for moving said slotrelative to said valve pin for controlling the rate of flow ofpressurized fluid through the metering passageway.

11. A time delay apparatus as defined in claim 8, wherein: saidaccumulator means includes means for partially enclosing the accumulatorpressure fluid engaging end of the accumulator piston when it is in theinoperative position so as to provide an increased piston fluid pressureworking area after the initial opening movement of the accumulatorpiston.

12. A time delay apparatus as defined in claim 10, wherein: saidmetering valve tube is disposed in said body perpendicularly to the lineof fluid flow through said body, and said tube extends through saidchambers and said valve bore.

13. A time delay apparatus as defined in claim 3, wherein: saidaccumulator chamber includes a piston cylinder portion and saidaccumulator piston is a differential piston operatively mounted in saidpiston cylinder portion and is provided with a reduced end extended intothe free flow fluid chamber, and, means for venting said piston cylinderportion of the accumulator chamber to the exterior of the body.

14. A time delay apparatus as defined in claim 3, wherein: saidpressurized fluid metering means includes a metering fluid passagewayinterconnecting said control fluid chamber and said accumulator chamber,and, a pressurized fluid inlet valve in said metering passageway andshiftable to an open position by fluid entering the metering passageway,and being in communication with said free flow fluid chamber andshiftable by fluid under pressure in said free flow fluid chamber to aclosed position to block said metering passageway when a predeterminedpressure differential exists between the fluid pressure in said controlfluid chamber and the fluid pressure in said free flow fluid chamber.

15. A time delay apparatus for controlling the flow of pressurized fluidin a fluid circuit, comprising: a body having a first port and a secondport; a passageway formed through said body for connecting said portsand including a control fluid chamber and a free flow fluid chamberconnected by a valve bore; a flow valve operatively mounted in saidvalve bore for controlling pressurized fluid flow therethrough and beingshiftable between a closed position and an open position; meansengageable with said flow valve for positioning the flow valve in one ofsaid positions, accumulator means in said body movable relative to andengageable with said flow valve for positioning the flow valve in theother of said positions after a predetermined time delay; and,pressurized fluid metering means in said body connected to said controlfluid chamber for admitting a metered flow of pressurized fluid from thecontrol chamber into said accumulator means to maintain a constantrelationship between the pressurized fluid in the fluid circuit and thepressure required to operate the accumulator means in a predeterminedtime cycle for timing the operation of the accumulator means.

References Cited by the Examiner UNITED STATES PATENTS 2,201,513 5/1940Ackerman 137-50543 X 2,676,612 4/ 1954 Stevenson 1-37490 X 2,680,4536/1954 Prijatel 137-490 2,830,784 4/1958 Placette 251-50 X 2,981,2774/1961 Gilmont 137-509 X 3,004,686 10/ 1961 McKee 137-5 05 .25 X

ISADOR WEIL, Primary Examiner. H. WEAKLEY, Assistant Examiner.

1. A TIME DELAY APPARATUS FOR CONTROLLING THE FLOW OF PRESSURIZED FLUIDIN A FLUID CIRCUIT, COMPRISING: A BODY HAVING A FIRST PORT AND A SECONDPORT; A PASSAGEWAY FORMED THROUGH SAID BODY FOR CONNECTING SAID PORTS; AFLOW RATE OPERATIVELY MOUNTED IN SAID PASSAGEWAY FOR CONTROLLINGPRESSURIZED FLUID FLOW THERETHROUGH AND SHIFTABLE BETWEEN A CLOSEDPOSITION AND AN OPEN POSITION; MEANS ENGAGEABLE WITH SAID FLOW VALVE FORPOSITIONING THE FLOWL VALVE IN ONE OF SAID POSITIONS; ACCUMULATOR MEANSIN SAID BODY MOVABLE RELATIVE TO SAID FLOW VALVE AND ENGAGEABLE WITHSAID FLOW VALVE FOR POSITIONING THE FLOW VALVE IN THE OTHER OF SAIDPOSITIONS AFTER A PREDETERMINED TIME DELAY; AND, PRESSURIZED FLUIDMETERING MEANS IN SAID BODY FOR ADMITTING A METERED FLOW OF PRESSURIZEDFLUID INTO SAID ACCUMULATOR MEANS FOR OPERATING THE SAME IN THEPREDETERMINED TIME DELAY FOR OPERATING THE SAME IN THE PREDETERMINEDLATOR MEANS.